Folding jaws cylinder

ABSTRACT

A folding jaw cylinder utilizes folding jaw pairs that automatically adjust the folding gap between the two jaws in each pair in response to the thickness of the folded product. A dual working chamber piston-cylinder unit is placed between first and second rotational carriers of the folding jaw members. One of the chambers is filed with liquid and is linked to a hydraulic accumulator by ways of a flow control valve. The second chamber is provided with compressed air.

[0001] The invention relates to a folding jaw cylinder for a foldingapparatus of rotary printing presses in accordance with the preamble ofclaim 1.

[0002] A folding jaw cylinder with a device for adjusting the foldinggap in accordance with the thickness of the product to be folded isknown from DE 25 37 920 A1. This adjustment is performed in thatinitially a sliding element with inclined faces is moved by means of athreaded spindle, which is supported on a threaded bushing and extendsin the axial direction of the cylinder. Thereafter, hingedly seatedplungers extending in the radial direction of the cylinder are actuatedby means of the inclined faces.

[0003] However, in connection with said folding jaw cylinder it isdisadvantageous that during the start-up of, for example, a collectionproduction with triple collection, it loses the products as often, i.e.two or three times, as the preset folding jaws receive a product of afinal product thickness.

[0004] It is the object of the invention to produce a folding jawcylinder.

[0005] In accordance with the invention, this object is attained by thefeatures of the characterizing portion of claim 1.

[0006] The advantages which can be achieved in particular by means ofthe invention reside in that in its basic position the folding jawopening is adapted automatically to the product thickness. This meansthat the thickness of a folding product taken over by the folding jawsat the start-up of multiple collection production is “sensed”.

[0007] In this way, regardless of its thickness, each folding product isindividually grasped, for example during the start-up of a production ofmultiply-collected folding products, in such a way that its sliding outof the folding jaw openings is prevented.

[0008] An exemplary embodiment of the invention is represented in thedrawings and will be described in greater detail in what follows.

[0009] Shown are in:

[0010]FIG. 1, a schematic representation of a longitudinal sectionthrough a folding law cylinder, approximately corresponding to the lineI-I in FIG. 4,

[0011]FIG. 2, a section II-II in accordance with FIG. 1 with an enlargedrepresentation of a diaphragm cylinder-piston unit;

[0012]FIG. 3, a section III-III in accordance with FIG. 1 with anenlarged representation of a synchronizing device;

[0013]FIG. 4, a cross section IV-IV through the folding jaw cylinder inaccordance with FIG. 1.

[0014] In a known manner, a folding jaw cylinder 1 consists of a firstsupport body 2, which is rotatably seated on a shaft 2 and has twolateral disks 4, 6 embodied as solid disks. The lateral disks 4, 6 arespaced apart and connected with each other by, for example four crossbars 5, which receive fixed folding jaw elements 7 evenly distributedover the circumference of the disks. The folding jaw cylinder 1furthermore has a second support body 8, which is also rotatably seatedon the shaft 2. The support body 8 is formed by two lateral disks 11,12, which are spaced apart from each other and are maintained atcylinder width by a number of supports 9. The lateral disks 11, 12 arepartially cut open (FIG. 4). On its circumference this second supportbody contains, for example, four controllable folding jaw elements 13,which are also evenly spaced. These folding jaw elements 13 arerespectively fastened, for example next to each other, on a spindle 14,seated fixed in place on the support body. At one end the spindle 14projects out of the support body 8 and is connected via a lever arm 16and a cam roller 17 with a control cam 18, which is fixed in place on alateral frame. The control cam 18 has a curve bottom 20 for opening anda curve bottom 25 for closing the folding jaw elements 7, 13. Thecontrol cam 18 is represented in dash-dotted lines (FIG. 4). A torsionbar 15 is located in the hollow spindle 14, one side of which isfastened on the disk 12 and the other side on the lever arm 16. In asimplified way, in FIG. 1 the position of the folding jaw elements 7, 13is represented offset by 45° in respect to the position of the foldingjaw elements 7, 13 in FIG. 4.

[0015] The shaft 2 of the folding jaw cylinder 1 is seated in lateralframes 22, 23 and is rotatable by means of rolling bearings 19, 21. Onone end, the shaft 2 is connected, fixed against relative rotation, witha drive gear wheel 24. The drive gear wheel 24 meshes with a drive gearwheel, not represented, of a collection cylinder, for example.

[0016] On the drive side, the shaft 2 has a collar 26 between thelateral frame 22 and the folding jaw cylinder 1. The collar 26 isconnected, fixed against relative rotation, with a drive disk 27, forexample by means of screws. The drive disk 27 extends parallel with thelateral disk 4 of the first support body 3 and rests against it (FIG.1).

[0017] The lateral disks 4, 11, as well as the drive disk 27 each have arespective recess 28, 29, 31, preferably on the drive side of thefolding jaw cylinder 1. A work cylinder 32, for example a double-actioncylinder-piston unit 32, 33, is arranged in the recess 28, 29, 31. Thework cylinder 32 is connected with the lateral disk 11 by means of aholder 40, attached to its housing 35, and a screw 72. The free end ofthe piston rod 34 is connected via a screw 73 with the lateral disk 4.

[0018] The cylinder-piston unit 32, 33 is suitably designed as adiaphragm cylinder. This means, for example, that the piston 33 isembodied in a disk shape and has a circular ring-shaped diaphragm 36 onits periphery. The diaphragm 36 is fixed in place by its exteriorcircumference on the housing 35 of the cylinder 32. This can be achievedby clamping it in place between two housing elements, for example. Inthis way a gas- and liquid-proof separation is achieved between a firstchamber 37 of the cylinder 32 and a second chamber 38 of the cylinder32. A piston stroke of this cylinder 32 is only a few millimeters (FIG.2).

[0019] The first chamber 37 is filled with a pressure medium 43, forexample hydraulic fluid. The chamber 37 is connected via an outletconnector 39, as well as a line 41, with a known energy accumulator, forexample a hydraulic reservoir 42, which is fastened, for example on asupport 9 of the second support body 8. On the side close to the line,the hydraulic reservoir 42 contains a fluid, and a gas 44 in anexpandable, or respectively compressible plastic bag. This gas can beair or nitrogen.

[0020] A throttle check valve 46 is arranged between the first chamber37 of the cylinder 32 and the hydraulic reservoir 42 and acts in thedirection toward the hydraulic reservoir 42.

[0021] The second chamber 38, filled with the gas 44, of the cylinder 32is connected via an outlet connector 27, as well as a line 48, with acompressed air source, not represented. Here, the line 48 first extendsinside the shaft 2. A known rotary inlet 49 located at the shaft endmakes a connection with a line 51 continuing to the compressed airsource (FIG. 1).

[0022] A synchronization device 52 is located in a recess 53, 54, 56 ofthe disks 4, 11, 27. The synchronization device 52 is locatedapproximately diametrically opposite the cylinder-piston unit 32, 33 andcan be arranged on the drive disk.

[0023] The synchronization device 52 consists of a synchronizing coupledgear. At one end of its recess 56, the drive disk 27 is fixedlyconnected with an L-shaped bearing block 57. The shorter leg of thebearing block 57 is made fork-shaped. A two-armed lever 59 is guided inthe fork 58, which is seated centered on a bearing bolt 61. The bearingbolt passes through the fork 58 in the radial direction toward thelateral disk 4, 11. The ends 62, 63 of the two-armed lever 59 arehingedly connected with first ends 64, 66 of couplers 67, 68. A secondend is hingedly connected at the end of the recess 54 with the lateraldisk 11 of the second support body 8 of the folding jaw cylinder 1. Asecond end 71 of the second coupler 68 is hingedly connected in theopposite direction from the end 69 of the first coupler 67 at the end ofthe recess 53 with the lateral disk 4 of the first support body 3. Thecouplers 67, 68 extend in the shape of a secant in respect to thelateral disks 11, 4.

[0024] In the top view (FIG. 3), the synchronization device 52consisting of the two-armed lever 59 and the two hinged couplers 67, 68represents a reflected letter Z.

[0025] The function of the folding jaw cylinder is as described in whatfollows. In the course of drawing a paper web into a rotary printingpress, or respectively an associated folding apparatus, the folding jawcylinder 1 turns at a low number of revolutions, i.e. at creep speed.Since there are no products yet to be received in the folding flaps 7,13, the compressed air supplied to the second chamber 38 of thecylinder-piston unit 32, 33 causes the fluid located in the firstchamber 37 to slowly flow into the hydraulic reservoir 42 via the line41, as well as through the throttle check valve 46 acting in thethrottling direction. In this case the air pressure is approximately 3to 6 bar and is higher than the pressure acting in the first chamber 37.In place of the chamber 38 charged with compressed air, the counterforcecan also be generated by a spring. Because of this, the two supportbodies 3, 8, and therefore the folding jaw elements 7, 13, move towardeach other in opposite directions until a preset gap of a minimum widthof, for example, 0.1 mm, constituting a basic setting, has been reached.

[0026] This gap can be preset by means of a stop. For example, the stopconsists of a bearing block 74, which receives a lockable screw 76 andis fastened on the lateral disk 4. One end of the screw 76 cooperateswith the lateral disk 11 (FIG. 4).

[0027] As soon as a first product has been transferred by a collectingcylinder to the folding jaw cylinder 1, the movable folding jaw elements13 are controlled via the cam gear 14, 16, 17, 18 so that they close. Inthe course of this a force is generated between the folding jaw elements7, 13, which pushes the folding jaw elements 7, 13 apart in accordancewith the thickness of the product.

[0028] This force, generated by the product and acting on the workcylinder 32 works, together with the force of the first chamber 37,against the force of the second chamber 38. In the process, the fluid israpidly drawn from the hydraulic reservoir 42 to the second chamber 37of the cylinder-piston unit 32, 33 without a throttling effect of thethrottle check valve 46. But a return movement of the piston 33 in thedirection of the second chamber 38 filled with compressed air only takesplace as far as the counterforce of the compressed air supplied via therotary inlet 49 will permit.

[0029] After the removal of the folded product from the folding jawelements 7, 13 of the folding jaw cylinder 1, the counterpressureprovided by the folded products no longer exists. The air pressureprovided via the rotary inlet 49 acts on the piston 33 of thecylinder-piston unit 32, 33. Here, the fluid in the first chamber 37tries to run off into the hydraulic reservoir 42 against the directionof the throttling effect of the throttle check valve 46. But this isprevented, depending on the setting of the throttle check valve 46, forexample because it is necessary that a thicker product must be picked upby the following next but one folding jaw elements 7, 13. As a result, aforce is again created between the folding jaw element 7, 13 afterclosing. Therefore the first and second support bodies 3, 8 turn furtherapart. In the course of this, the piston 33 moves in the direction ofthe second chamber 38 filled with compressed air, until the cam roller17 has reached the highest point of the control cam 18 and the foldingjaw elements 7, 13 are closing again. In the process the fluid in thefirst chamber 37 again tries to run off into the hydraulic reservoir 42against the direction of the throttling effect of the throttle checkvalve 46.

[0030] Thus, the first chamber 37 of the work cylinder 32, 33 is chargedwith a pressure medium, wherein the supply and removal of the pressuremedium takes place with different amounts per unit of time (the supplytakes place at a greater speed than the removal). Here, the speed of thesupply is a multiple of, i.e. at least twice, the speed of the removal.

[0031] When after several collections the final thickness of the producthas been reached, the folding jaws 7, 13 have been set to thisthickness.

[0032] After increasing the rpm of the machine, a hydraulically,pneumatically or mechanically acting known blocking device can becomeautomatically active, which fixedly connects the lateral disks 11, 4with the drive disk 27.

[0033] The synchronization device 52 sees to an even setting of thefolding jaw gap in both directions.

[0034] It is also possible to utilize a different gear with little playand less automatic locking for the synchronization device.

[0035] The work cylinder 32 can also be arranged between a support bodyand a folding jaw element, which is movable in relation to it, orbetween a control element, for example the cam roller 17, and theassociated folding jaw element.

REFERENCE NUMERALS

[0036]1. Folding jaw cylinder

[0037]2. Shaft (1)

[0038]3. Support body, first

[0039]4. Lateral disk (3)

[0040]5. Cross bars

[0041]6. Lateral disk (4)

[0042]7. Folding jaw element, fixed

[0043]8. Support body, second

[0044]9. Support (11, 12)

[0045]10. -

[0046]11. Lateral disk (8)

[0047]12. Lateral disk (8)

[0048]13. Folding jaw element, controllable

[0049]14. Spindle

[0050]15. Torsion bar

[0051]16. Lever arm

[0052]17. Cam roller

[0053]18. Control cam

[0054]19. Rolling bearing

[0055]20. Curve bottom (18)

[0056]21. Rolling bearing

[0057]22. Lateral frame

[0058]23. Lateral frame

[0059]24. Drive gear wheel

[0060]25. Curve bottom (18)

[0061]26. Collar (2)

[0062]27. Drive disk

[0063]28. Recess (4)

[0064]29. Recess (11)

[0065]30. -

[0066]31. Recess (27)

[0067]32. Cylinder

[0068]33. Piston

[0069]34. Piston rod

[0070]35. Housing (32)

[0071]36. Diaphragm (33)

[0072]37. Chamber, first (32)

[0073]38. Chamber, second (32)

[0074]39. Outlet connector (37)

[0075]40. Holder

[0076]41. Line (39)

[0077]42. Hydraulic reservoir

[0078]43. Fluid

[0079]44. Gas

[0080]45. -

[0081]46. Throttle check valve (41)

[0082]47. Outlet connector (38)

[0083]48. Line

[0084]49. Rotary inlet (2)

[0085]50. -

[0086]51. Line

[0087]52. Synchronization device

[0088]53. Recess (4)

[0089]54. Recess (11)

[0090]55. -

[0091]56. Recess (27)

[0092]57. Bearing block (52)

[0093]58. Fork (57)

[0094]59. Lever, two-armed (52)

[0095]60. -

[0096]61. Bearing bolt (59)

[0097]62. End (59)

[0098]63. End (59)

[0099]64. End, first (67)

[0100]65. -

[0101]66. End, first (68)

[0102]67. Coupler, first (52)

[0103]68. Coupler, second (52)

[0104]69. End, second (67)

[0105]70. -

[0106]71. End, second (68)

[0107]72. Screw (4)

[0108]73. Screw (11)

[0109]74. Bearing block (4, 76)

[0110]75. -

[0111]76. Screw, lockable (74)

1. A folding jaw cylinder (1) with at least one folding jaw having twofolding jaw elements (7, 13), wherein a gap between these folding jawelements (7, 13) can be set to a thickness of products to be processed,characterized in that a device (32, 42, 46) for the automatic adjustmentof the gap between the folding jaw elements (7, 13) is provided.
 2. Thefolding jaw cylinder (1) in accordance with claim 1, characterized inthat the device (32, 42, 46) has at least one work cylinder (32), whichis connected with an energy accumulator (42), wherein the supply andremoval of a pressure medium (43) takes place at different amounts perunit of time.
 3. The folding jaw cylinder (1) in accordance with claim2, characterized in that a throttle check valve (46) is arranged betweenthe work cylinder (32) and the energy accumulator (42).
 4. The foldingjaw cylinder (1) in accordance with claim 2, characterized in that thework cylinder (32) can be charged with a counterforce.
 5. The foldingjaw cylinder (1) in accordance with claim 4, characterized in that thework cylinder (32) is charged with a second pressure medium (44).
 6. Thefolding jaw cylinder (1) in accordance with claim 2, characterized inthat the work cylinder (32) is arranged between the support bodies (3,8), which can be moved toward each other, of the folding jaw elements(7, 13).
 7. The folding jaw cylinder (1) in accordance with claim 2,characterized in that the work cylinder (32) is arranged between asupport body and a folding jaw element, which can be moved in relationto the support body.
 8. The folding jaw cylinder (1) in accordance withclaim 2, characterized in that the work cylinder (32) is arrangedbetween a control member (17) for moving a controllable folding jawelement (13) and the folding jaw element (13).
 9. The folding jawcylinder (1) in accordance with claim 1, characterized in that thedevice (32, 42, 46) increases the width of the gap at a first speed andreduces the width of the gap at a second speed, wherein the first speedis greater than the second speed.
 10. The folding jaw cylinder (1) inaccordance with claim 9, characterized in that the first speed is amultiple of the second speed.